


The Captastic Voyage

by Hakaishin02



Category: The Avengers (Marvel Movies), The Avengers (Marvel) - All Media Types
Genre: Anal, Body Exploration, Body Hair, Canon-Typical Violence, Consensual Sex, Don't Like Don't Read, Endosomatophilia, Farting, First Kiss, Foot Fetish, Graphic description inside someone's body, Hydra (Marvel), M/M, Macro/Micro, Macrophilia, Masturbation, Mind Control, Mouthplay, Non-Consensual Somnophilia, Not Actually Unrequited Love, Oral Sex, Rape/Non-con Elements, Scat, Shrinking, Unaware, Urethral Play, Vore, Watersports, crushed under foot, gore/death, microscopic
Language: English
Status: In-Progress
Published: 2020-07-30
Updated: 2020-07-31
Packaged: 2021-03-05 21:53:34
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,529
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25602373
Author URL: https://archiveofourown.org/users/Hakaishin02/pseuds/Hakaishin02
Summary: As Captain America battles soldiers, terrorists, and villains of all kinds, unbeknownst to him, a microscopic alien race has invaded his body, planning a hostile takeover of him. When Ant-Man and some of his teammates delve into the depths of the soldier’s body, they uncover a microscopic society of humans who have lived inside Cap since he was given the serum. As they explore the wondrous and treacherous world inside Cap’s body, they learn that the world beneath their feet is more complex and vast than they could have imagined. They must save both worlds from an unprecedented threat without Cap knowing anything is amiss.
Relationships: James "Bucky" Barnes/Steve Rogers, OC/OC, Scott Lang/OC, Scott Lang/Steve Rogers
Comments: 3
Kudos: 20





	1. A Dream Interrupted

**Author's Note:**

> Hello, 
> 
> So this is my first story on this site. For those reading this written work, I do hope you will enjoy it. If the above-mentioned tags dissuade you from reading this, please do not read this story. While I do not have this story completely planned out, I have a general idea of where I want this story to go. However, I would love to hear any constructive input. I will also be editing the story as I see fit so I will be sure to update any changes to the story as I post chapters. 
> 
> This story will contain multiple convergent plots and parallel POV. Enjoy!
> 
> As Captain America slumbers, a microscopic alien race enters his brain.

_Looking back, it has been a bizarre week at the Tower, even for us. Sure, we’ve witness some extraordinary things almost on a weekly basis. It comes with being an Avenger. But the situation we face right now was certainly over the top, for me at least. Where I lay face down on the ground most definitely was over the top because of the vast swathe of pliant pasty sole that reeked of cheesy-sweat descending towards me. Darkness descends upon me as long, curved toes with square-pad endings rolled over me. Being stepped on by Captain America is not how I envisioned myself kicking the bucket. Flakes of dead skin rains downward from the clammy sole of Cap’s foot._

_In the end, a phone call would save my life._

_I know. Sounds bizarre._

_My name is Scott Lang, aka Ant-Man._

_This is what happened._

**Cap’s Brain, 2:49 a.m.**

**T** he void was enormous, black and starless. Though stentorian lightning flashed and clapped violently, illuminating an endless primeval forest of gray spidery roots and vines.

Bathed in cerebrospinal fluids, Cap’s brain shuddered loudly from an unconscious shifting of his head on his pillow.

Scintillating pulses coursed the crisscrossing organic wiring of his brain, carrying his memories, experiences and thoughts like deliverymen transporting packages to their destinations. Somewhere in the ripples of light was a lustful dream of a dick inside him. Butthole stretched. Lips to the nape of his sweaty neck.

Breathing deeply, he spun long strands of sticky precum from his shaft. His mouth was open and stifled moans poured out of him. Those muffled grumbles echoed through the cortex from outside.

An efflux of synaptic signals surged through axons and jumped across dendrites into the hippocampus, instructing it to tap into past sexual memories and erotic fantasies from someplace deep down his walled mind to be painted across the inside of his eyelids like a movie on a projector screen. A neural storm raged in the amygdala, provoking repressed romantic emotions into the forefront.

Outside, they twitched subtly as he dreamed.

Released into the synaptic space between dendritic endings, clouds of dopamine incited the pleasurable feelings of arousal Cap was feeling at that moment as violent impulses surged down the spinal cord from the brain to the thick cock that erected and to the strong hand that gripped it.

Erratic thrums of his heartbeat resounded in the clear watery fluids before echoing into the dark recesses beyond.

Another quiet night inside his head.

But not business as usual.

Just before three that morning, in the cerebral bowels of Captain America’s brain, a whirling vortex hung in the void between a cluster of neurons like a pendant, green in the ether light casted by tempestuous synapses.

Deep, in the tangles of smooth neurons that bordered that brain’s motor center, a pewter-silver frigate drifted into the ocean of cerebrospinal fluid.

It scraped roughly over a tendril of grey matter as a spheroid of pure neural electricity was crossing it, carrying inside it a snapshot memory from his youth of Cap’s first trip to a Brooklyn Dodger’s game and the emotions it carried with it. The tendril jolted from the abrupt jerk and scattered the synaptic impulse into oblivion. A memory of a brief moment in Cap’s life was expunged from his mind along with the sentimental attachments it fostered within him, as if it never existed.

Personality and mindset altered so subtly it wouldn’t have changed him at all. But he would never know.

The alien vessel landed atop a neuron after maneuvering through the tangled webs of grey matter.

The ship had a thick metallic hull, incongruous with the organic surroundings. It engulfed the neuron, hung to the semipermeable membrane with heavy clamps.

The neuron and its tree-like extensions shuddered briefly from the extra weight.

Inside, the unseen invaders observed meticulously at the vast wiring of the unwitting man’s cerebral cortex, content to relish the moment.

It was finally time.

As ordered, the attack was about to begin.

From its underside, an injector gouged the fatty gray membrane as metallic tendrils snaked across the axons and dendrites.

The injector then halted, siphoning a heady banquet of electricity and chemicals. Cap’s mind was like an open book to them. His thoughts and memories became indecipherable coding, displayed on their screens. What he was dreaming materialized for all to witness like a movie. The privacy of his heart and mind breached.

They saw Cap’s frenzied hand jerking himself off as the hazy image of another man rocked into him.

From outside, their organic world rumbled. The muffled wail of Cap’s hoarse moans bounced around the interior of his head.

A blaring reverberated from the vessel — loud and artificial, it was unmoving for long moments before a hangar door opened up.

The suited aliens walked onto the membrane, nervous, alert to danger.

They trekked higher up the nearby densities of the neuron. They chirred to each other.

“Listen to that, sir,” one said stoically, distant heartbeat and low-pitched moans loud enough to hear through flesh.

Trilling uncaringly, the high-ranking soldier surveyed the organic terrain, covered with insulating fat. So strange but familiar to him.

This would be an easy conquest _,_ he thought.

He then stiffened like a feral dog guarding pups. Indiscernible eyes bored into a buoy-like structure at the root of the axon and approached it with curious fingers.

What is this? Why is it here? It isn’t ours.

“What do surmise it is?” His subordinate had walked up from behind.

The metal-paneled walls and grey-colored flesh that propagated over it, almost infused together, clearly spouted to him as fabricated by hand.

“Securing this beachhead won’t be like the others it appears.”

Behind him, the Keep tore through the axon and their world trembled.

It was a quiet night inside Cap’s brain. The synapses flickered very brilliantly throughout the wide expanse of the cerebrum. It became quieter and quieter as it spread away into the fringes of the brain against wall of the cranium, with contorted streaks of lightning searing up the hilly landscape of the frontal lobe into the meningeal skies of connective tissues where a clear sea of cerebrospinal fluid bathed the spidery ventricles. Through the calcified ceiling of his skull and the uneven, perforated desert of his cream-colored epidermis between his dark brows, Captain Steve Rogers was breathing heavily, sweat making his pale skin shine in the dim glow of the moon outside.

The smell of precum and his damp foreskin was in the air.

He thought about Scott Lang, imagining the man holding him down and ramming him until he cried out.

A tantalizing knot formed at the base of Steve’s spine, a ball of electricity gathering there that made his muscles jerk.

His hefty balls drew up as he was about to make one more stroke of his dick.

That moment, inside his head, a slender tendril of grey matter snapped. A minuscule tearing of neural wiring jumbled up his brain pattern for a half-second and Steve abruptly clutched his head from the brief moment of discombobulation.

He groaned softly as his approaching high suddenly faded away. The thick erection that had flopped down began to soften.

What was that? Steve thought.

He’d never know.


	2. The Subtle Art of Intimacy

**Summary for the Chapter:**

> The Subtle Art of Intimacy: A Love-struck Ant-Man treasures his teammate and leader, Captain America, intimately while he slumbers peacefully, unaware of his shrunken teammate walking across his body.

The nightstand clock said 4:30 a.m. Scott Lang had been up for about an hour that night, flying on the back of an ant fifteen minutes, lounging briefly in Caps’ musky undergarment chucked on the floor ten minutes, and basking in the manly stench inside of Cap’s boot at the foot of his bed five minutes. Sleep was wasted on him. He hadn’t the mindset for a good night sleep without blowing off some steam first. 

That moment, Scott was quickly ascending up the hanging bed sheets — on his way to Steve and Bucky’s slumbering forms, where he’d be admiring their shapely physiques. By which he meant: Sex. 

He had a suit that gave him the ability to shrink to the zip of an ant while gaining superhuman durability. While he had promised Hank Pym that he wouldn’t misuse the Ant-Man technology — which meant not using it for opportunistic reasons, like to have my way with Captain Rogers without him every knowing, he was lonely and downright horny as fuck, why not? Besides, he couldn’t help himself because he was nuts about Steve. 

Steve Rogers, aka Captain America, invaded this thoughts persistently since their first meeting in Germany. Scott saw how fucking gorgeous Cap was — the sleek muscles, that cream-colored skin, the spick and span look of his messy-pomaded hair with very soft spikes, and those eyes glinting blue like the open sea. 

His breathing shifted and his arousal was palpable thinking like that. Scott felt embarrassed as he recalled geeking out meeting his childhood idol. He was glad that Steve was patient with him. However, he has wrestled with these budding feelings for his teammate, leader, and friend since he joined the team on a permanent basis. He has hidden his heart from Rogers with awkward camaraderie and private anguish. This wasn’t a crush; this was love, pure and simple. 

Every woman around and himself gawked mindlessly like a lovesick school girl at Cap whenever he strode down the hallways of SHIELD HQ in his uniform. Muscles, flawless skin, intense eyes, plump buttocks — the epitome of sex and masculinity. Scott held his breath. This was the man he has dreamt about almost every night. 

These thoughts were drifting through his mind as he reached the top of the bed. Scott moistened his lips. He’d be lying if he said his heart didn’t kick into high gear at that moment. Like before, he had waited for him to fall asleep so he could partake his night of secret pleasure. 

Screw it. He had it bad for Steve. 

Scott — from his perspective as a quarter-inch-tall man — saw that men were lying flat on their backs with the bedsheets in a tangled mess around them, one naked foot peeking out underneath. Their meaty curves were accentuated by the covers and a puddle of brightness thrown by the full-moon outside. The silver light of the moon just caught in the locks of Steve’s blond hairs, like an aura. 

Gentle snores rumbled loudly through the air. Bucky had one of his legs thrown over Steve and was snuggled up against his side, his warm breath ghosting his sweaty shoulder. The cold-blooded mercenary was such a softy. 

Just the sight of them and Scott started to get an erection and his balls shifted, but before he could rub a guilty hand over them, Steve rolled away from Bucky toward the edge of the bed and onto his stomach, pulling off the covers to unveil more of a perfect body. Cap’s naked body stretched out on the bed like a mountain, his muscled legs spread apart, revealing the plump curve of his buttocks that shook slightly from the abrupt movement. 

“Fuck, Steve.” Scott muttered, looking down the long legs to admire Steve’s bunched crotch. Just peeking between his thick thighs, his silky, fat balls loose in the wrinkled sack that pinned his uncircumcised dick. It was as if Captain was tempting him. “It’s moments like this that I’m so happy to be Ant-Man.” 

After all, he got the Ant-Man suit and a supply of Pym particles to live out his secret fantasies. After a while, Scott had started to become aware of Steve’s habits. For example, Steve often had to go missions far away for long periods of time, so his dirty undergarments would stay in the hamper, unwashed, for several days. It was during those long periods of time that he would indulge in deviant behavior. 

He’d shrink down and crawl into Cap’s sweaty briefs like going into a dingy cave. He would nuzzle his face where Steve’s cherubic butt would spend hours infusing his musky odor and staining the fabric with drippings of sweat and smudges of his shit. He would undress out of his suit just enough to expose his hard cock, and he would jerk off directly onto the fabric wall, inhaling his unique smell. 

_ Damn, his ass smelled so good, so fucking good _ , Scott reminisced. Scott knew it was a really weird thing to do, but what harm was he causing. It wasn’t like Cap was getting hurt in any way, right? 

Scott clenched his fists and held his breath for a moment, with his dick at full-mast. “It’s just you and me, Cap” 

Scott darted across the bed, which from his tiny perspective, was the size of an endless tarmac at one of the big airports, turning toward the closest foot. The bedsheets were the same whitish-beige as the floor carpeting of the bedroom, but rather than the faint odor of laundry detergent, in the cotton there was the scent of soot and gunmetal. There was another smell, too, faint and very tempting. Sweat. Musk. Cum. Scott smirked at the faint signs of coitus between the two men. 

“Looks like I missed out already.” He was sure of that. “But it doesn’t mean that I can’t still enjoy myself.” 

Scott slowly approached the colossal foot of the sleeping giant, which looked as huge as a ferris wheel. Because Steve was lying on his stomach, he had an attractive view of his soft sole as he looked up the damp skin. He felt his dick painfully pressing against the inside of his suit. 

He could still feel the light moisture on the soldier's sole in the air and breathed in that funky odor, the result of his hot feet being jammed into those socks and boots for so long during his recent assignment. 

He retracted his faceplate and breathed in heavily, shoving his face into the moist crevice between the big toe and one next to it, filling his nostrils with his manly aroma. 

He moaned softly, aroused from a heady bouquet of sweat and cheesy odor. It sent shivers up and down his spine, caressing the soft skin of the underside of his toes and licking the pasty skin to feel the grooves of the skin and to taste the tanginess of budding toe grime. There was even a ball of lint stuck to his tongue. His feet looked so pristine but between his toes, it was a cesspool of nastiness. Clearly, the man hadn’t showered yet and washed his feet. 

“Damn it, Rogers. So hot. It’s so fucking…hot,” Scott muttered. “What I wouldn’t do to feel your feet squeeze my dick.” 

He tenderly embraced the odd-shaped but adorable big toe and briefly rubbed his erection against the digit before looking up at the pale sole. Scott knew he had to move on. 

He climbed over the long, curved digits and hiked up the sole, noticing loose strands of hair and pellets of grime stuck to the pasty skin. He reached the top of the heel, where the skin was tautened from calluses. There, he had a picturesque view of Captain America’s bodily landscape before him. 

Under the pale glow of the moon, the undulating hills and valleys of Cap’s unmoving form was framed beautifully, the smooth plains of his broad back, the round swell of his butt, and the tight muscles of his long legs. 

_ Simply beautiful _ , Scott thought, looking down the man’s parted legs towards his crotch where his pearl-pink balls and slender shaft were nestled. The sight made him salivate more than he already was. He felt his heart pounding through his chest while he sprinted down the back of Steve’s muscled leg. The moon’s glow glinted off the small hairs peppered from up the back of the thigh, then up the slope of the round asscheek, and dipping into the snug cleft of his butt. 

Standing atop the cheek, Scott was offered a wondrous panorama of the entire bed. Butt hairs speckled both smooth, firm cheeks like an unseen meadow. The skin was so pale from lack of exposure to sunlight and barely dipped under his weight. He shifted from foot to foot, feeling the muscle and fat that comprised these glutes. He glanced lovingly at his Cap’s sleeping face. So relaxed he was. 

Scott heard a soft popping sound, followed by a pungent odor of rotten eggs. He breathed in the putrid stench with fondness. Asleep, Steve grunted briefly while he emitted another soft fart from his rear. He moaned quietly in relief. 

“I think he ate too much chili last night,” Scott whispered, walking towards the dark crevice of the ass. Another deep rumbling from between his legs told Scott that Cap had farted again. He could feel the heat of it. Scott was so hard that moment. Like an excited fan, he jumped into the tight crack, squeezing between the mounds of fat and muscle. He grabbed onto the wiry hairs to tug himself deeper into Cap’s beefy bum, inching closer to the pink butthole. 

Eventually, he reached his intended destination: Cap’s hairy asshole. It was dark here from the lack of light but he could feel the quivering folds of the anus. He took some time to properly worship the most sacred and intimate spot on Steve’s person. He caressed the deep wrinkles with his gloved hand and his tongue, tasting the tanginess of his musky sweat and Bucky’s dried-up cum that was plastered within the folds. Desire surged inside him as he eyed the filthy hole. He had touched it many times before, but the sight of it never failed to arouse him. He wanted to do so much more. 

Steve grunted and with a soft sigh, let loose a deep, booming fart. The tightly puckered hole opened up and Scott really felt the hot gas pass from the puckering anus with a look of ecstasy on his face. It smelled thick and spicy. 

“Enough of that. It’s time now to really fuck him,” Scott whispered, rubbing his hardening dick against the muscled flesh. He crawled back and stripped the suit off until the lower half was around his ankles. He sniffed again at the dull odor that settled in the canyon of his butt. 

He kneeled down and brought his face down to kiss the edge of the hole. The sweat and gunk of the day spent working in the field and trips to the toilet had gathered there and dried. This was pure Steve. He shoved his leaking cock between two folds and began to thrust. He buried his face against the outer edge, smelling the lingering musk. He was soaking the flesh with his precum. 

“Oh my God, Steve! Oh fuck! You feel so…so good!” Scott wailed at the top of his lungs. His cries of pleasure bounced around the snug walls of ass but never resounded past the hairy crack. Steve slept on, unaware consciously of Scott’s presence. 

Scott drove his dick into the flexing heat of flesh and stayed planted, so deep. Steve grunted as a discomforting pressure moved downward from his intestines to his rectum. At that moment, Scott briefly glanced at the dusky hole beside him through the jungle of hairs. So abruptly, the anus quivered and a steady stream of popping farts rumbled out, blasting his face. It had a sharp, potent stink, heavy, and rotten. His ass hairs blew with his wind. 

With that Scott roared —- spasmed and tightly dug into the anal folds, crying and groaning as hot spirals of cum splattered the pink surface. His smell was everywhere: sweat, musk, and the funk of his semen. It mixed with Steve’s, blending into a euphoric odor. Scott rode the feeling as far as he could until he gathered his thoughts and strength to stumble back onto his feet. 

Panting heavily, Scott was dazed, leaning against the wall of ass, the fat dipped when he pressed against it. “I love you. I love you, Steve.” 

“I want,” Scott kissed the warm skin softly, “to be with you.” Steve unconsciously clenched his buttocks from a slight irritation at his hole and Scott felt it. With heartache, he imagined being compressed between the two mounds of fat and muscle was Steve’s way to comfort him lovingly. He knew it was true, but it helped to think that. 

Suddenly, the pressure was gone and then the flesh beneath him quaked. Scott stumbled backwards as a gigantic finger pushed into the tight ass. “Fuck!!” 

Scott jumped out of the way as the thick finger dove into the anus, distorting the natural shape of the butthole. It dragged across the edge of the anus, the trimmed fingernail scratching the skin and accumulating cum both dry and wet underneath. The larger man hummed in relief. Scott sighed and watched the large finger stop and rise out of the ass. 

“That was close,” Scott said, pulling up his pants. “I gotta be more careful next time.” Chucking to himself, he jumped out of the buttcrack, cautiously ran across the silky underside of Cap’s balls, and jumped onto the bed sheets. There, he casually walked out between the soldier’s legs as he was already thinking of what his next endeavor would be. 

_ I wonder if…. _

  
  


**Notes for the Chapter:**

> Chapter 3: Eyes of Blue: A man’s life of toil for our regarded Captain is brought to an end by a foreseen tragedy. Meanwhile, Natasha notices Cap acting strangely as Bucky and Sam confront him about his pining for a certain man. 
> 
> (Chapter plot subject to change)


End file.
